Hey all,
 
I am having an issue, whenever I start my computer it powers up, led lights on the case are on and the fan is working however nothing happens, the OS does not boot, the screen does not go on. ( yes my screen works 100 % , already tested it). So when i turn the comp back off, the led light around power button turns off however the led light at the upper case still stays on and the fan even spins harder, can anyone please help me out ? removed some cables inside and ram but with no result..
 
 
 
I didn't find the right solution from the internet.
References:

 

 
 

Can you load the BIOS? 
 
This is usually done by holding down the <del> key while powering on.
 
If you can the next thing I would check is the boot drive, specifically can the BIOS see your normal C: drive.
 
If you can load the BIOS and the C: drive is visible, I would try booting from another device i.e. the CD Drive.
 
Difficult to say what to do next...

Does it beep? The first thing the CPU does is run a little sanity check called the POST (power-on self-test) that makes sure the most important stuff is working, and issues a series of beeps when something goes wrong. If you get no beeps at all, your motherboard is dead. The last time this happened to me it was defective capacitors on the MB shorting the +5V rail. 
 
Before you freak out, make sure the power supply is good. It can fail and still have lights lit, because it provides multiple voltages for different things and not all of them are responsible for lights lighting up. That's a 50-dollar repair.

Yes start with the bios. 
If you are still stuck this forum here is the best nerd squad for issues. They have never failed me in 20 years. 
http://forums.ncix.com/
 
We also have a computer forum here but most of those guys also check this hardware forum to as it's almost the same idea. 
 
   Bitflipers comment about beeps is also a big clue, Modern Mobos like mine also have a small LED with numbers and this gives you a trouble code,, You'll need the Mobo manual. 

What Bitflipper said.  It does a POST but if no display it suggests the BIOS is not starting.  Thus the power supply is one suspect.  Because you have been inside, a loose or missing cable is a good possibility.
 
What PC do you have?  Would help us to try and help you. 
 
I belong to several computer forums with lots of hardware people on them.  Such as  www.tenforums.com 
www.sevenforums.com 
 

Another option:  The video device you're connecting to the monitor for whatever reason is no longer the default device.  This can happen with systems that have on board video + a discreet graphics card.
 
If you have a motherboard with video output, try connecting your monitor to that during power up and see if you get anything.  Try any and all other video outputs, including and in particular good old analog VGA.

First thing I'd do is re-seat the RAM and video card.
If it still doesn't post... I'd try booting with a single stick of RAM in the outermost RAM slot.
If that fails, try another RAM stick in that same slot.

If you are Linux savvy, you can boot to a USB drive to diagnose.

I had a friend bring his PC to me with the same symptoms. Power on, fans spin, and that was it.
 
It was an HP desktop, and it turned out that it needed a new motherboard.  Upon close examination, several capacitors on the mobo were bulging.
 
To troubleshoot, I hooked up a spare power supply, and tested the RAM one stick at a time, but no go.  I was lucky to be able to locate a reasonably priced refurb mobo on eBay for his model (out of warranty, and out of production).
 
In this case, there were no beeps, no POST, nothing on display.  So the damaged board would not even load the BIOS.

johnnyhenderson
Hey all,
 
I am having an issue, whenever I start my computer it powers up, led lights on the case are on and the fan is working however nothing happens, the OS does not boot, the screen does not go on. ( yes my screen works 100 % , already tested it). So when i turn the comp back off, the led light around power button turns off however the led light at the upper case still stays on and the fan even spins harder, can anyone please help me out ? removed some cables inside and ram but with no result..
  
I didn't find the right solution from the internet.
References:
 

Is this legit or are the references we can't read spam of sorts?
A couple of thoughts. I assume you are talking about case fans or fan. Although it's weird for a case fan to spin faster upon power off, if the OS isn't booting. How do you know the OS isn't booting?
One clue is if you have a video card with fans - then upon power up of the case the video card fans usually spin faster until the OS kicks in and the graphics software stabilizes the fan speed, so that they noticeably slow or quieten down.
 
It's always hit and miss. If I were a betting man, and you hadn't moved or knocked the PC recently, I would say change the CMOS battery on the motherboard and reboot. The CMOS battery is the small flat disc battery on the motherboard. You can pick them up at most convenience stores. Just get the same type - the number is on the top.
2 cents